The sacroiliac joint is formed by the meeting of the sacrum (at the base of the spine) and the ilium (at the upper part of the pelvis). Treatment for indications such a pain at the sacroiliac joint includes fusing the sacrum and ilium together. The Assell et al. U.S. Patent Application Publication No. 2011/0166575, for example, discloses a sacroiliac fusion system including associated surgical instruments and methods. A bone screw that can be used in connection with sacroiliac fusion procedures is disclosed in the Assell et al. U.S. Patent Application Publication No. 2012/0323285. Both of the above-identified Assell patent application publications are incorporated herein by reference for all purposes. There remains a continuing need for improved sacroiliac joint fusion fasteners (such as screws) and associated instruments and procedures.